The present application relates to a method of making iron powder by reducing iron oxides to produce powder particles having fiber-like configuration and texture.
U.S. Pat. No. 3,975,186 discloses a method of making fibrous iron powder particles by spray calcination of a pickling solution that was used for pickling iron and steel. The resulting iron oxide particles were reduced in a CO atmosphere at a temperature between 800.degree. and 1000.degree. C. This patent discloses also that an SO.sub.2 content in excess of 1% of the CO content in the reducing atmosphere positively interfers with the fiber formation; so does an excessive amount of H.sub.2.
This method is quite practical but depends on spray calcination to obtain iron oxide as intermediate raw material. Other iron oxides, e.g. ore, cannot be used or only with inadequate yield for making fibrous iron powder through the reducing process as outlined in that patent. However, it is apparent that iron oxides generally, and particularly ores, are readily available raw materials. Therefore, it is quite desirable to use them in some fashion for making iron powder.